In the current information age, the amount of data handled by society has increased dramatically. This has greatly increased demand for devices that can input, output, and store large amounts of data at very high speeds. One type of magnetic recording and playback device is a hard disk drive. Another type of storage device is a magnetic tape drive. The recording density of magnetic storage devices has steadily increased as perpendicular magnetic recording techniques have been adopted and improved. Currently available magnetic recording devices have the capability of recording magnetic data at a recording density of 650 Gb/in2, but there are problems with thermal fluctuation in these magnetic recording media. Increasing the anisotropic energy of magnetic recording media has been an effective countermeasure, but a sufficient magnetic recording field cannot be generated using a very small magnetic recording head such as would be used in high density recording. Because of this, recording densities have been limited to about 1 Tb/in2.
Assisted recording technologies are currently being researched as a solution to enable recording beyond the 1 Tb/in2 limit, thereby allowing higher magnetic recording densities. Assisted recording technologies can include a recording technology such as shingled recording, wherein a magnetic signal can be written using a magnetic write head with a magnetic write pole width that is larger than the recorded track width. The use of magnetic microwaves or thermal energy have also been explored to assist recording of high-density magnetic information on narrow magnetic tracks.
Playing back magnetic information written to narrow magnetic tracks and converting this information to electrical signals, requires a narrow-track sensor. However, the width of the sensor has a large effect on the sensitivity of a sensor, and the target playback amplitude (S) is not sufficient for a width of 30 nm in magnetic disk devices exceeding 1 Tb/in2. As the width of the recording track becomes smaller, the effect of crosstalk noise from adjacent magnetic information tracks becomes significant. As a result, a signal-to-noise (S/N) ratio needed to realize 1 Tb/in2 cannot be satisfied.
A technique that counters this crosstalk phenomenon has been disclosed in US Patent Application No. 2012/0205830. In this technique, magnetic signals are played back using a plurality of sensors. While this patent application discloses the use of a plurality of sensors it does not provide a sensor arrangement that can solve the problem of crosstalk from adjacent magnetic tracks. Therefore, there remains a need for a system or structure that can reduce or eliminate such adjacent track cross talk at very tight track pitches in order to effectively increase data density beyond the 1 Tb/in2 limit.